In approximately the early 1960's, nonwoven fabrics began to be used in lieu of the conventional woven fabrics for blankets, bed coverings and like products, particularly for the more expensive uses of such products. Manifestly, nonwoven fabrics were much cheaper to produce than the heretofore conventionally utilized woven fabrics and could be napped to provide raised fiber surfaces on each of the faces thereof to produce a product which was very similar to woven blankets and the like.
One of the problems which arose in the early designing of constructions of nonwoven fabric, which would be suitable for use as blankets in lieu of the previously utilized woven material, was in providing sufficient strength to the blanket fabric in both the widthwise and lenghtwise directions which was easily obtained in the previous conventionally utilized woven blanket material. Although nonwoven fabric constructions of the chemically bonded type and of the densely needled type had previously been utilized for other products which would provide sufficient strength, these nonwoven fabric constructions lacked the desired flexibility and drapability for fabric utilized as blankets and the like.
Many nonwoven fabric constructions were proposed by various manufacturers for use as blankets and the like which purportedly provided desired strength and stability in the fabric in both the widthwise and lengthwise directions, while providing the desired flexibility and drapability. For the most part, these nonwoven fabric constructions included at least three superimposed layers of material in which the outer facing layers consisted of carded and cross-lapped textile fibers having the fibers thereof oriented in the widthwise direction for providing strength and stability to the fabric in the widthwise direction and a reinforcing middle layer or scrim which provided strength and stability to the fabric in the lengthwise direction.
An example of such a fabric construction which has been highly commercially successful is disclosed in U.S. Pat. No. 3,260,640, issued July 12, 1966, and assigned to the assignee of the present invention. As may be seen in this patent, the nonwoven fabric for use as blankets and the like was formed with outer layers of carded and cross-lapped textile webs forming outer facing layers having the fibers thereof oriented in the widthwise direction for providing strength and stability to the fabric in the widthwise direction and a reinforcing middle layer or scrim consisting specifically of an Arachne stitched fibrous web which provided strength and stability to the fabric in the lengthwise direction. Also, a number of manufacturers utilized a reinforcing middle layer or scrim consisting of a layer of spun yarns laid down between the outer layers in the lengthwise direction of the fabric for providing strength and stability to the fabric in the lengthwise direction.
Both of the above two described three-layer fabric constructions were then needled with a conventional needling machine forming a desired number of needled fiber entanglements interlocking the fibers of the layer with each other and forming an integrated needled nonwoven fabric. The number of needled fiber entanglements formed in the fabric was selected to provide the desired flexibility and drapability to the blanket fabric and not produce an unduly hard or boardy fabric which would not be suitable for use as blankets and the like.
While the above nonwoven fabrics have been successfully commercially produced now for a number of years and have replaced the previously conventional woven fabrics for a substantial portion of the blanket fabric market and have provided sufficient strength in both the widthwise and lengthwise directions while providing flexibility and drapability suitable for use of the fabrics as blankets, the processes and apparatus utilized for producing these blankets have been necessarily slow resulting in a more expensive resulting needled nonwoven fabric.
In this regard, the speed of production of the three-layer blanket fabric by the above described processes and apparatus was limited to the speed of operation of the cross-lapping mechanisms receiving webs of textile fibers being produced by carding machines and cross-lapping these webs onto a moving conveyor for building up of the three-layer fabric. Since the cross-lapping machines by design cross-lapped the carded webs back and forth onto a moving conveyor, the speed of operation was necessarily less than the speed in which the carded webs were produced by the carding machines.